Your electricity budget is not always the same as the amount available to buy kWh. South African prepaid tariffs may include service charges, tax, lifeline allowances and increasing block prices.
First check the tariff
Look at your latest token receipt to identify the actual units received and your effective rate. A simple average is the rand amount actually applied to energy divided by the units received. If R500 effectively purchases 160 kWh, your observed rate is about R3.13 per kWh.
Why the same R500 can buy fewer units
If tariff blocks are based on monthly purchases or consumption, later purchases can fall into higher-priced tiers. Fixed deductions can also reduce the amount allocated to energy. Do not assume each recharge starts a new tariff block.
Try a budget first
Use the prepaid electricity calculator to change rates and fixed deductions. It is a model, not a verified supplier tariff.
Read the receipt before trusting the price per unit
The number on a prepaid token may represent the energy credit added to the meter, not every charge associated with the transaction. Depending on your municipality and tariff category, fixed amounts, arrears recovery, levies or taxes may affect what portion of a cash payment becomes units. Where a stepped tariff applies, two purchases of the same rand amount at different points in a billing period can also yield different units.
Use a repeatable personal method: save the rand amount paid, the number of kWh credited and any visible deductions from the receipt. For a rough effective rate, divide the energy spend by units credited. Repeat over several purchases, since a single receipt may be affected by a block boundary or administrative charge.
Four questions worth asking the supplier
Which tariff category is the meter on? Are there service charges or fixed deductions? When do block quantities reset? Does the quoted price include VAT? The answers let you replace this site's illustrative inputs with your actual local rules.
Municipal tariffs and electricity purchase arrangements change. We therefore do not label any example amount on this site as an official October 2026 electricity price. Use your municipality's published tariff schedule or account for a current quote.